Provision of downlink packet access services to user equipment in spread spectrum communication network

ABSTRACT

A method of providing a packetized data transmission service to a mobile terminal ( 108 ) in a spread spectrum communication network ( 100 ), includes: at a transmitter ( 102 ), broadcasting an indication message to a cell on a downlink broadcast channel ( 114 ), the indication message providing notification of an available packetized data transmission service intended for the mobile terminal ( 108 ); at the mobile terminal ( 108 ), monitoring the broadcast channel ( 114 ) for the indication message, and upon receipt, acknowledging detection of the indication message to the transmitter ( 102 ) on an uplink contention channel ( 116 ); and at the transmitter ( 102 ), upon contention completion, transmitting packetized data transmission service configuration information to the mobile terminal ( 108 ) on the broadcast channel ( 114 ).

CROSS REFERENCE

This application is a Divisional of U.S. patent application Ser. No.12/064,796, filed Feb. 25, 2008, and is a national phase applicationunder 35 U.S.C. §371 of International Patent Corporation TreatyApplication No. PCT/JP06/317148, filed Aug. 24, 2006, which claimspriority to Australian Patent Application No. 2005904679, filed Aug. 26,2005. The contents of each of these referenced applications isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to the provision of downlinkpacket access services to a mobile station in a spread spectrumcommunication network. The invention is suitable for use in theprovision of such services to a user equipment in a communicationnetwork conforming to the 3GPP-LTE standards being developed by the 3rdGeneration Partnership Project (3GPP), and it will be convenient todescribe the invention in relation to this exemplary, but non-limiting,application.

PRIOR ART

Recent enhancements in packet transmissions such as High Speed DownlinkPacket Access (HSDPA) and enhanced uplink technology have made 3GPPradio-access technology highly competitive. In order to ensure that thecompetitiveness of this technology continues over a long time frame, along term evolution of 3GPP radio-access technology is being developed.This new technology is known as Super 3G

Important parts of the long term evolution of Super 3G technology willinclude Radio Access Network (RAN) latency reduction, higher user datarates, improving system capability and coverage, and reducing cost to anetwork operator. In order to achieve this, an evolution of the radiointerface as well as the radio network architecture is being considered.The objective of this evolution is to develop a framework to enable highdata rate, low-latency and packet-optimized radio-access.

Development of the Super 3G system has been focused on supportingservices provided by the PS-domain, such as enhanced HSDPA, MultimediaBroadcast Multicast Services (MBMS), High Speed Uplink Packet Access(HSUPA) and other similar types of packet-switched services includingVoice Over IP.

Existing HSDPA services in Wideband Code Division Multiple Access(WCDMA) systems are currently provided in a manner that is dependent onother dedicated RAN services. This results in an extremely complicatedprotocol stack design, and hinders the development of HSDPA services inWCDMA.

The Super 3G system will be developed to support enhanced HSDPA andother types of packet-switched services. However, reusing the existingHSDPA-related procedures that have been developed for the WCDMA systemwill lead to a situation where the future 3G system shall be coupledwith and operationally dependent on existing WCDMA technology. Thisinterdependence is likely to result in an even more complicated RANarchitecture, which will then increase the cost of design, manufactureand operation of the Super 3G system.

There therefore exists a need to enable enhanced HSDPA services to beintroduced into the future Super 3G system in such a manner as to beable to operate independently from the existing 3G-WCDMA system whenconsidered from the RAN perspective. There also exists a need to provideenhanced HSDPA services in a manner that ameliorates or overcomes HSDPAservice provision techniques.

DISCLOSURE OF THE INVENTION

In one aspect of the present invention, there is provided a method ofproviding a packetized data transmission service to a mobile terminal ina spread spectrum communication network, the method including at a basestation, broadcasting an indication message to a cell on a downlinkbroadcast channel, the indication message providing notification of anavailable packetized data transmission service intended for the mobileterminal, at the mobile terminal, monitoring the broadcast channel forthe indication message, and upon receipt, acknowledging detection of theindication message to the base station on an uplink contention channel,and at the base station, upon contention completion, transmittingpacketized data transmission service configuration information to themobile terminal on the broadcast channel.

The method may further include the steps of periodically placing themobile terminal in an active state to monitor the broadcast channel forthe indication message, and placing the mobile terminal in an inactivestate, if no indication message is detected.

The method may further include the step of at the base station,transmitting control information for the packetized data transmissionservice to the mobile terminal on a downlink shared control channel.

The method may further include the step of at the base station,transmitting data for the packetized data transmission service to themobile terminal on a downlink shared data channel.

The method may further include the step of at the mobile terminal,transmitting channel quality measurement and reporting information tothe base station on an uplink shared scheduled channel.

The method may further include the steps of ceasing transmission fromthe base station of packetized data transmission control information tothe mobile terminal, and upon failure to detect the packetized datatransmission control information at the mobile terminal within apredetermined time, terminating the packetized data transmissionservice.

The method may further include the steps of at the base station,notifying the mobile terminal to terminate the packetized datatransmission service by inclusion of a termination message in a packetheader of an packetized data transmission control information packet,and upon detection of the termination message at the mobile terminal,terminating the packetized data transmission service.

For instance, the mobile terminal is comprised of a mobile phone.

In another aspect of the present invention, there is provided a methodof controlling an operation of a base station for providing a packetizeddata transmission service to a mobile terminal in a spread spectrumcommunication network, the method including broadcasting an indicationmessage to a cell on a downlink broadcast channel, the indicationmessage providing notification of an available packetized datatransmission service intended for the mobile terminal, the mobileterminal monitoring the broadcast channel for the indication message,and upon receipt, acknowledging detection of the indication message tothe base station on an uplink contention channel, and upon contentioncompletion, transmitting packetized data transmission serviceconfiguration information to the mobile terminal on the broadcastchannel.

The method may further include the step of transmitting controlinformation for the packetized data transmission service to the mobileterminal on a downlink shared control channel.

The method may further include the step of transmitting data for thepacketized data transmission service to the mobile terminal on adownlink shared data channel.

The method may further include the steps of ceasing transmission ofpacketized data transmission control information to the mobile terminal,and upon failure to detect the packetized data transmission controlinformation at the mobile terminal within a predetermined time,terminating the packetized data transmission service.

The method may further include the steps of notifying the mobileterminal to terminate the packetized data transmission service byinclusion of a termination message in a packet header of an packetizeddata transmission control information packet, and upon detection of thetermination message at the mobile terminal, terminating the packetizeddata transmission service.

In still another aspect of the present invention, there is provided aprogram for causing a computer equipped in a base station to carry outthe above-mentioned method.

In yet another aspect of the present invention, there is provided asystem for providing a packetized data transmission service in a spreadspectrum communication network, the system including a base station anda mobile terminal, the base station being adapted to broadcast anindication message to a cell on a downlink broadcast channel, theindication message providing notification of an available packetizeddata transmission service intended for the mobile terminal, the mobileterminal being adapted to monitor the broadcast channel for theindication message, and upon receipt, acknowledging detection of theindication message to the base station on an uplink contention channel,and the base station being further adapted, upon contention completion,to transmit packetized data transmission service configurationinformation to the mobile terminal on the broadcast channel.

In the above-mentioned system, the mobile terminal may be comprised of amobile phone.

In still yet another aspect of the present invention, there is provideda base station in a system for providing a packetized data transmissionservice in a spread spectrum communication network, the system includingthe base station and a mobile terminal, the base station being adaptedto broadcast an indication message to a cell on a downlink broadcastchannel, the indication message providing notification of an availablepacketized data transmission service intended for the mobile terminal,the mobile terminal being adapted to monitor the broadcast channel forthe indication message, and upon receipt, acknowledging detection of theindication message to the base station on an uplink contention channel,and the base station being further adapted, upon contention completion,to transmit packetized data transmission service configurationinformation to the mobile terminal on the broadcast channel.

The present invention will now be described in reference to the attacheddrawings in which a method and system of providing a High Speed DownlinkPacket Access (HSDPA) service is illustrated as a preferred embodiment.It is to be appreciated that the invention is not to be construed asbeing limited to the particular embodiment illustrated in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a spread spectrumcommunication system in which an HSDPA service is provided from a basetransceiver station to a user equipment.

FIG. 2 is a timing diagram illustrating the functional steps performedat both the base transceiver station and the user equipment duringnotification, acknowledgement, performance and termination of the HSDPAservice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments in accordance with the present invention will beexplained herein below with reference to drawings.

Referring now to FIG. 1, there is shown generally a spread spectrumcommunication network 100 including a base transceiver station (BTS) 102operably connected to a radio transmission tower 104, and a userequipment (UE) 108.

For instance, the user equipment 108 is comprised of a mobile phone.

The base transceiver station (BTS) 102 and the radio tower 104 areoperably connected to a communication network (Super 3G network) 106conforming to the Super 3G system being developed by the 3GPP.

The base transceiver station 102 communicates with the user equipment108 whilst the user equipment 108 is located within a broadcast cell110. Control information and data is exchanged between the basetransceiver station 102 and the user equipment 108 during the provisionof High Speed Downlink Packet Access (HSDPA) services by means of achannel structure 112 including a downlink (DL) broadcast channel 114,an uplink (UL) reserved channel (contention) 116, a downlink (DL) sharedcontrol channel 118, a downlink (DL) shared data channel 120, and anuplink scheduled channel (shared control channel and physical controlchannel) 122.

For instance, the base transceiver station 102 includes a centralprocessing unit (CPU), a first memory, a second memory, an inputinterface through which a command and/or data is input into the centralprocessing unit, an output interface through which a result of stepshaving been executed by the central processing unit is output, and a busthrough which the central processing unit is electrically connected withthe first memory, the second memory, the input interface, and the outputinterface.

Each of the first and second memories and is comprised of asemiconductor memory such as a read only memory (ROM), a random accessmemory (RAM) or an IC memory card, or a storage device such as aflexible disc, a hard disc or an optic magnetic disc.

For instance, the first memory comprises a read only memory (ROM), andthe second memory comprises a random access memory (RAM).

The first memory stores therein a program for causing the centralprocessing unit to carry out a method of controlling an operation of thebase transceiver station 102 for providing a packetized datatransmission service to the user equipment 108 in a spread spectrumcommunication network. The second memory stores therein various data andparameters, and presents a working area to the central processing unit.The central processing unit reads the program out of the first memory,and executes the program. Thus, the central processing unit operates inaccordance with the program stored in the first memory.

Referring now to FIG. 2, when the user equipment 108 moves within thebroadcast cell 110, both the base transceiver station 102 and the userequipment 108 act at step 200 to allow the user equipment 108 toregister with the Super 3G network 106 and thereby enable the basetransceiver station 102 to communicate directly with the user equipment108.

At step 202, the base transceiver station 102 transmits synchronizationinformation to the user equipment 108 on a synchronizationchannel/common pilot channel in order for the user equipment 108 todetect relevant information sent to the user equipment 108 in datapackets.

Upon receipt of the synchronization information at step 202, the userequipment 108 performs, at step 204, cell search, frame timingdetection, symbol timing, and scrambling code detection functions inaccordance with conventional WCDMA techniques to enable communication tobe established between the Super 3G network 106 and the user equipment108.

When an HSDPA service is to be provided to the user equipment 108, anindication message is prepared at step 206 to be broadcast to the entirecell 110, the indication message being encoded in such way that it canbe decoded and identified by the user equipment 108 by a specific userequipment identification number that is allocated to the user equipment108 by the Super 3G network 106 at step 200. The indication message actsto notify the user equipment 108 of an available HSDPA services intendedfor the user equipment 108.

The encoded information is then broadcast at step 208 on the downlinkbroadcast channel 114 (set of sub-carriers), the user equipment 108being informed of the downlink broadcast channel 114 upon registrationwith the Super 3G network 106 at step 200.

At step 210, the user equipment 108 is normally in an inactive (sleep)state, except for predetermined periods of time when, in step 212, theuser equipment 108 is placed in an active (wake-up) state in order tomonitor the downlink broadcast channel 114 for indication messagestransmitted from the base transceiver station 102.

If no indication message is detected, the user equipment 108 is onceagain placed in an inactive state.

However, if an indication message is detected, the user equipment 108processes the indication message, and transmits an acknowledgement 214of detection of the indication message to the base transceiver station102 on the uplink reserved channel 116 using a contention approach. Theuplink reserved channel information on which the acknowledgement 214 istransmitted is indicated to the user equipment 108 in the indicationmessage.

The base transceiver station 102 monitors the uplink reserved channel116 at step 216 for the acknowledgement 214.

Upon receipt of the acknowledgement 214 from the user equipment 108, thebase transceiver station 102 informs the user equipment 108 about thecontention completion, and starts to prepare and transmit the RAN HSDPAservice configuration information 218 on the downlink broadcast channel114, at a time and frequency allocated for this task. This downlinkbroadcast channel 114 is monitored only by the user equipment(s) 108that previously sent an acknowledgement 214 to the indication message.

Upon successful completion of the contention, the user equipment 108prepares to receive data on the downlink broadcast channel 114 at apredetermined time after completion of the contention, at step 220. Theconfiguration information received on this channel assists the userequipment 108 to perform layer 1 (physical layer), layer 2 (mediumaccess control/radio link control), and layer 3 (Radio Resource Controllayer) configuration to monitor the downlink shared control channel 118,configuring the Hybrid Automatic Repeat Request (HARD) related functionsand performing channel quality measurement and reporting.

Once the configuration has taken place at step 220, the user equipment108 starts performing, at step 222, channel quality measurement, andmonitoring of the downlink shared control channel 118 to detect fastsignaling intended for the user equipment 108 and other existing HSDPArelated procedures for receiving data on the downlink shared datachannel 120.

Accordingly, channel quality information (CQI) 224 is transmitted fromthe user equipment 108 to the base transceiver station 102 according toa preconfigured schedule in order to provide the base transceiverstation 102 with information as to which frequency chunk in the downlinkshared data channel 120 is best suited for the particular user equipment108 in order that frequency scheduling can be optimized.

The channel quality information 224 is transmitted on the uplinkscheduled channel 122. Once the base transceiver station 102 hasreceived initial channel quality information 224, the base transceiverstation 102, at step 226, performs channel scheduling and sends fastsignaling information 228 on the downlink shared control channel 118 tothe user equipment 108.

The associated packet data 230 is then sent on the downlink shared datachannel 120 to the user equipment 108. At step 232, the user equipment108 keeps monitoring the downlink shared control channel 118 on theallocated time-frequency slot.

Once the user equipment 108 detects control information intended forthat user equipment 108, the user equipment 108 starts to receive anddecode the associated packet data 230 transmitted on the downlink shareddata channel 120.

The result of the data packet reception (ACK/NACK/POST/PRE/DTX for H-ARQprocessing) 234 is then reported to the base transceiver station 102 onthe associated uplink scheduled channel 122.

Similarly, the channel quality information (CQI) 236 for the downlinkpacket scheduling is again transmitted on the uplink scheduled channel122.

At step 238, once the H-ARQ feedback information and channel qualityinformation has been received, the base transceiver station 102 performsAdaptive Modulation and Coding (AMC), scheduling and retransmission foreach user equipment 108. Retransmission occurs if a NACK message isreceived from the user equipment 108.

The above-mentioned steps 228 to 238 are then repeated at both the basetransceiver station 102 and the user equipment 108 during provision ofthe HSDPA service to the user equipment 108.

Once the HSDPA service provided to the user equipment 108 is to beterminated, the base transceiver station 102 may simply stoptransmission of control information on the downlink shared controlchannel 118 to the user equipment 108, at step 240.

In this case, upon failure of the user equipment 108 at step 242 todetect HSDPA control information within a predetermined time, the HSDPAservice is terminated and the user equipment 108 is again placed in aninactive state.

Alternatively, the HSDPA service can be terminated by inclusion of thetermination message in a packet header of an HSDPA control informationpacket sent to the user equipment 108 on the downlink shared datachannel 120. Upon detection of the termination message at the userequipment 108, the HSDPA service may be terminated.

From the foregoing, it will be appreciated that the above-describedmethod for providing an HSDPA service to a user equipment advantageouslyintroduces a specific paging procedure and specific paging indicationfor an HSDPA service without requiring use of a dedicated data channelas currently described in WCDMA networks.

Moreover, the above-described method introduces a sleep mode to allowthe Super 3G user equipment to save power when in use. A new channel isintroduced to establish the Radio Resource Control (RRC) layer peer topeer communication for HSDPA RAN configuration, rather than relying upona dedicated channel as in current WCDMA systems.

A packet transmission termination scheme is also introduced at the radiointerface level to allow either the base transceiver station 102 toterminate a downlink packet transmission either temporarily orpermanently whilst minimizing the exchange of traffic via the airinterface between the base transceiver station 102 and the userequipment 108.

Finally, it is to be appreciated that various modifications andadditions may be made to the above-described method of providing a highspeed downlink packet access service to a user equipment in the spreadspectrum communication network without departing from the spirit orambit of the invention.

1. A spread spectrum communications system for providing a packetizeddata transmission service, comprising: a base station; and a userequipment, wherein the base station broadcasts to a cell an indicationof the packetized data transmission service on a downlink broadcastchannel, wherein the user equipment monitors the downlink broadcastchannel for the indication of the packetized data transmission servicefrom the base station, wherein the base station transmits packetizeddata transmission service configuration information to the userequipment on the downlink broadcast channel, and wherein the userequipment has two states that comprises an active state to monitor thedownlink broadcast channel and an inactive state.
 2. The spread spectrumcommunications system of claim 1, wherein the user equipment transmitsto the base station an acknowledgement of detection of the indication.3. The spread spectrum communications system of claim 1, wherein thebase station transmits control information for the packetized datatransmission service to the user equipment on a downlink shared controlchannel, wherein the user equipment monitors the downlink shared controlchannel for the control information for the packetized data transmissionwherein the base station transmits data for the packetized datatransmission service to the user equipment on a downlink shared datachannel.
 4. The spread spectrum communications system of claim 3,wherein the user equipment utilizes the packetized data transmissionservice configuration information to monitor the downlink shared controlchannel for the control information for the packetized data transmissionservice.
 5. The spread spectrum communications system of claim 1,wherein the user equipment report to the base station channel qualityinformation.
 6. The spread spectrum communications system of claim 1,wherein the base station transmits to the user equipment an indicationof termination of the packetized data transmission service on a downlinkshared control channel.
 7. The spread spectrum communications system ofclaim 1, wherein the indication comprises a notification of thepacketized data transmission service.
 8. A communications methodimplemented in a base station for providing a packetized datatransmission service in a spread spectrum communications system,comprising: broadcasting to a cell an indication of the packetized datatransmission service on a downlink broadcast channel; and transmittingpacketized data transmission service configuration information to a userequipment on the downlink broadcast channel, wherein the user equipmentmonitors the downlink broadcast channel for the indication from the basestation, and wherein the user equipment has two states that comprises anactive state to monitor the down link broadcast channel and an inactivestate.
 9. The communications method of claim 8, wherein the userequipment transmits to the base station an acknowledgement of detectionof the indication.
 10. The communications method of claim 8, furthercomprising: transmitting control information for the packetized datatransmission service to the user equipment on a downlink shared controlchannel; and transmitting data for the packetized data transmissionservice to the user equipment on a downlink shared data channel, whereinthe user equipment monitors the downlink shared control channel for thecontrol information for the packetized data transmission service. 11.The communication method of claim 10, wherein the user equipmentutilizes the packetized data transmission service configurationinformation to monitor the downlink shared control channel for thecontrol information for the packetized data transmission service. 12.The communication method of claim 8, wherein the user equipment reportto the base station channel quality information.
 13. The communicationmethod of claim 8, further comprising: transmitting to the userequipment an indication of termination of the packetized datatransmission service on a downlink shared control channel.
 14. Thecommunication method of claim 8, wherein the indication comprises anotification of the packetized data transmission service.
 15. Acommunications method implemented in a user equipment for receiving apacketized data transmission service in a spread spectrum communicationssystem, comprising: monitoring a downlink broadcasst channel for anindication of the packetized data transmission service from a basestation, wherein the base station broadcasts to a cell the indication ofthe packetized data transmission service on the downlink broadcastchannel, wherein the base station transmits packetized data transmissionservice configuration information to the user equipment on the downlinkbroadcast channel, and wherein the user equipment has two states thatcomprises an active state to monitor the downlink broadcast channel andan inactive state.
 16. The communications method of claim 15, furthercomprising: transmitting to the base station an acknowledgement ofdetection of the indication.
 17. The communications method of claim 15further comprising: monitoring a downlink shared control channel for thecontrol information for the packetized data transmission service,wherein the base station transmits control information for thepacketized data transmission service to the user equipment on thedownlink shared control channel, and wherein the base station transmitsdata for the packetized data transmission service to the user equipmenton a downlink shared data channel.
 18. The communications method ofclaim 17, further comprising: utilizing the packetized data transmissionservice configuration information to monitor the downlink shared controlchannel for the control information for the packetized data transmissionservice.
 19. The communication method of claim 15, further comprising:reporting to the base station channel quality information.
 20. Thecommunications method of claim 15, wherein the base station transmits tothe user equipment an indication of termination of the packetized datatransmission service on a downlink shared control channel.
 21. Thecommunications method of claim 15, wherein the indication comprises anotification of the packetized data transmission service.